1. Field of the Invention
The present invention relates to a height adjusting apparatus for vehicle seats, and more particularly, a height adjusting apparatus for vehicle seats which is provided on a lower seat frame so as to adjust the height of a vehicle seat.
2. Description of the Related Art
As well known to those skilled in the art, a vehicle seat includes a seat part, which is placed underneath a passenger's buttocks to support the buttocks, and a back part, which supports the passenger's back. Conventionally, in order to tilt the back part backwards or straighten up the back part, a manual control device is provided. Further, in order to ensure legroom, the seat is constructed so that its seat part moves forwards or backwards. These days, such operation of the seat is performed using a motor and a gear assembly.
In a conventional vehicle seat, seat brackets, which are installed in a vehicle, are coupled to seat side frames provided on both side ends of a seat part, via links. In order to adjust the height of the seat, a gear assembly is mounted to the lower portion of the seat part, thus moving the seat part up and down by the rotation of a motor.
The conventional height adjusting apparatus for the vehicle seat is constructed so that a pinion gear is mounted to each seat side frame, and a rack gear is mounted to each link. Thereby, when the pinion gear is driven by the motor, the pinion gear is operated in conjunction with the rack gear, thus moving the seat part up or down.
However, the conventional height adjusting apparatus is problematic in that the seat cannot withstand inertia occurring in the event of a head-on collision, so that the raised seat is undesirably dislodged and quickly lowered, thus threatening the safety of a passenger. This is because the meshing force of the rack gear with the pinion gear is structurally weak.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.